Corrugated paper



Feb. 3, 1953 P. BROWN 2,627,484

CORRUGATED PAPER Filed March 50, 1951 vEN'roR l \I Pay/15m Patented Feb.3, 1953 CORRUGATED PAPER Paul Brown, Walpole, N. H., asslgnor toPackaging Materials Corp., a corporation of Rhode Island ApplicationMarch- 30, 1951, Serial No. 218,314

4 Claims. 1

This invention relates to packaging material such as used for thepackaging of glassware and other frangible objects, and is specificallyan improvement on the packaging material disclosed in the patent to E.L. Perry, No. 2,209,537.

Frangible articles packed with the packaging material described andclaimed in the above mentioned patent are much less subject to breakagethan when packed with straw and excelsior in the usual manner, and withthe new material forming the subject-matter of this application thebreakage is still further reduced, so that the loss from damage intransit of fragile glassware wrapped therein is almost negligible.

In the accompanying drawings I have illustrated my improved packingmaterial in the form of a flat sheet and also in certain modified forms,and in the said drawings.

Figure 1 is a perspective showing my improved packing material in flatform;

Fig. 2 is a sectional view on an enlarged scale of a portion of anarticle wrapped with my improved material;

Fig. 3 is a view similar to Fig. 1 showing a modified form of myimproved material; and

Fig. 4 is a sectional View showing the method of making a secondmodified form of my invention.

Referring to the drawings, I indicates a sheet of molded corrugatedpaper similar to that disclosed in the Perry patent above mentioned butwithout the backing sheet, therein described. This sheet is formed bymolding the pulp directly into a corrugated sheet in accordance with theprocedure described in Patent No. 2,221,200 also issued to E. L. Perry.

The molded corrugated sheet is preferably of the form shown in Fig. 1,consisting, as there shown, of ribs or corrugations 2 of molded pulpconnected by intermediate portions 3 also of molded pulp, which are softand flexible and substantially thinner than the corrugated portions. Theback of the sheet, as shown, is not smooth, but presents a roughair-dried finish with shallow grooves 3a underlying the corrugations 2.

A thin sheet 4 of flexible paper is cemented across the crowns of thecorrugations 2. Any suitable cement which does not significantly hardenor stiffen the paper may be used. A casein glue such as widely used inthe manufacture of coated paper is satisfactory. The sheet 4 is thinrelatively to the thickness of ribs 2, and flexible, but not extensible,and consequently when the packing sheet is wrapped around a fragilearticle,

as shown in Fig. 2, the inner, or intermediate, portions 3 of thecorrugated sheet between the corrugations 2 are bowed outwardly as shownat 5 to thereby form the contacting portions of the sheet with theenclosed article.

By the construction shown the article is protected against breakage toan extent not obtainable with any other form of packing material.Breakage of fragile articles results primarily from the impact of onearticle against another in the container if the container is droppedfrom an excessive elevation, and from the force of an external blow iftransmitted to the article adjacent the wall of the carton at the pointstruck. With my improved packing material the surfaces of the articlesare in contact only with the crowns of the curved thin portions 3 of thecorrugated sheet which are maintained in convex form by the thin backingsheet 4.

Thin frangible articles of glassware such as light bulbs, wine gobletsand the like, are usually light in weight and have little inertia.-Consequently when a package of articles packed with my improved packingsheet is dropped from an undue height the impact of dropping is readilyabsorbed by the portions 3 of the corrugated packing sheet which aresoft and yield readily under pressure of an article of light weight. Theconvex portions 3 of the corrugated sheet thus permit a sufficientmovement of the articles to absorb their momentum when the movement ofthe carton is suddenly stopped by contacting an unyielding surface. Themolded ribs forming. the corrugations are also quite soft and yielding,as pointed out in the above Perry patent, and will continue to absorbthe shock of impact should there be any movement of the articles afterthe cushioning effect of the intermediate part 3 is exhausted.

My improved packaging material also protects the article from breakagefrom an outside blow to a greater extent than the material described inthe above mentioned patent. A thin, frangible article will be crushedfrom the impact of an outside force if concentrated on a small area ofthe surface of the article but will not be crushed if the same force isdistributed over a substantially larger area. Hence if any fairly thinportions of the packing material which are in direct contact with thearticle are also in contact with the wall of the carton at the point ofimpact the article may be broken even though the carton is undamaged. Nosuch areas are present in my improved packing material, and unless thepressure on the carton or the force of the blow received by the cartonis suflicient to deform or rupture the carton the contents will not bedamaged.

The ribs 2 of my packing material are adjacent the walls of the cartonor packing case in which the article are packed and the force of a blowon the outside of the carton must be transmittedthrough the ribs 2 andintermediate portions 3be'fore reaching the article.

To increase the flexibility of the packaging material in a directiontransverse to the ribs forming the corrugations I may, before applyingthe backing sheet l to the molded corrugated board, score thecorrugatedface of the board 2 with a series of parallel score linesextending transversely of the ribs 2 forming the corrugations as shownat 6 in Fig. 3. The. score. lines may be formed in the board on theboard-makingv machine in the manner illustrated in the copendingapplication of Eugene L. Perry, Ser. No. 3 100;702, filed June 22, 1949,or the score lines may be -formed in the finished board by running thecorrugated sheets through scoring rollers having with the backing sheet4 shorter than the base of the sheet. As here shown, instead of gluingthe backing sheet to the corrugated sheet when the latter is supportedon a flat surface, the gluing is effected by pressing the corrugatedsheet, to which adhesive has been applied along the crowns of thecorrugation, against the backing sheet while the latter is passing overa backing roller, a portion of which is indicated at i. This method ofmanufacture can be readily carried out by a continuously operatingmachine, as will be obvious, and the Web so formed wound into a rollwith the backing sheet on the side toward the axis of the roll.

When the sheet is formed in this manner the intermediate portions 3 willbe bulged away from the backing sheet even when the sheet is Wrappedaround a flatided article, thereby producing an even greater cushioningeffect than .when the .sheet is formed in the manner shown inFig. 1.

Iclaim: 3 .1. Packaging material comprising a molde :sheet having spacedcorrugations connected by intervening, flexible portions, the materialin said corrugations being substantially thicker than the material insaid intervening portions, and a sheet of flexible, non-extensiblematerial attached to the crowns of the corrugations, said sheet beingrelatively thin in comparison to the thickness of the corrugations.

2. Packaging material comprising a molded sheet having spacedcorrugations, shallow grooves underlying said corrugations, saidcorrugations being connected by intervening, flexible portions, thematerial in said corrugations being substantially thicker than thematerial in said intervening portionaand a sheet of flexible,non-extensible materialattached to the crowns of the corrugations, saidsheet being relatively thin in comvparison to the thickness of thecorrugations.

3. Packaging material comprising a molded sheet havingspacedcorrugations connected by intervening flexible portions, thematerial in said. corrugations being substantially thicker than thematerial in said intervening portions, the face ofthe corrugationshaving spaced scorings extending to a depth less than the height of thecorrugations above the intervening portions, and a sheet of flexible,non-extensible material attached to the crowns of the scoredcorrugations, said sheet being relatively thin in comparison to thethickness of said corrugations.

4. Packaging material comprising a molded sheet having spacedcorrugations connected by intervening flexible portions, the material insaid corrugations being substantially thicker than the material in saidintervening portions, and a sheet of flexible, non-extensible materialattached to the crowns of the corrugations, said sheet being relativelythin in comparison to the thickness of the corrugations and the lengthof said sheet between its lines of attachment to said corrugations beingshorter than the distance between said corrugations'along the oppositesurface of the corrugated sheet.

PAUL BROWN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

1. PACKAGING MATERIAL COMPRISING A MOLDED SHEET HAVING SPACEDCORRUGATIONS CONNECTED BY INTERVENING, FLEXIBLE PORTIONS, THE MATERIALIN SAID CORRUGATIONS BEING SUBSTANTIALLY THICKER THAN THE MATERIAL INSAID INTERVENING PORTIONS, AND A SHEET OF FLEXIBLE, NON-EXISTENSIBLEMATERIAL ATTACHED TO THE CROWNS OF THE CORRUGATIONS, SAID SHEET BEINGRELATIVELY THIN IN COMPARISON TO THE THICKNESS OF THE CORRUGATIONS.